In dyeing methods, conventionally, various techniques have been employed such as hand-drawing dyeing, batik using wax as a dyeing preventive material, and paste pattern dyeing using paste as a dyeing preventive material.
For example, batik using wax as a dyeing preventive material is based on a technique by which a pattern is formed to produce a dyed material using wax melted through a paintbrush, brush or pattern and dyeing the material using the wax pattern formed as a dyeing preventive material, and then the wax is removed leaving a pattern where the wax covered the material. Paste pattern dyeing is based on a technique by which a dyed material is coated with a paste for preventing dyeing and after the paste coating has dried, the material is dyed and then rinsed with water to remove the paste.
However, dyeing techniques using handwork, as described above, require great skill on which the workmanship of the dyeing depends, and all such techniques have a limit in terms of the accuracy of the pattern depicted. Considerable time and labor are required to remove the wax preventing dyeing in certain areas, for the paste to dry and to rinse with water.
Also the blast processing technique, by which particles such as river sand and silica sand are injected with compressed air and blasted on to a work, has been conventionally used only for surface processing such as sand-removal of casts and debarring, and letter-engraving of gravestone and the like.
However, conventionally, there is not a technology using blast processing of a work surface to engrave the surface with a fine shape or letter or to carve a deep hole like a pot to perform technological engraving.
The reason is that conventional masks were produced in a primitive manner wherein a rubber plate is cut out by a cut knife, so that it is difficult to produce a fine mask, and the mask, adhering to an engraved surface, is easily teared off or turned up by injection pressure. If a mask is allowed to closely adhere to the engraved surface using an adhesive to prevent such trouble, tearing up becomes difficult.